Haiming Zhang^1,2,*, Shilin Zhao^1,2, Zhenshan Cui^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.08884

Abstract Particle-reinforced aluminum matrix composites (PRAMCs) have great potential for application in aerospace, automobile, defense, and electronics due to their high specific strength and stiffness and good resistance to wear and corrosion. Achieving a superior trade-off between the strength and ductility of PRAMCs necessitates an elaborative control of the microstructures, like the size and distribution of particles, as well as grain size, morphology, and texture of the matrix. The multiscale interaction between the particles and the matrix’s microstructure is insufficiently understood due to the lagging of high-resolved in-situ characterization. This work proposes a nonlocal physically based crystal plasticity (CP) modeling approach… More >

Shichao Luo¹, Yinan Cui^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010223

Abstract The responses of metals subjected to super high rates of deformation (> 10!/�), as shocking loading, is an area of active research. At such extreme loading rates, subsonic, transonic, and even supersonic dislocation (compared with the shear wave speed in metals) play a crucial role in plastic deformation. The behavior of high-speed dislocations is much more complex than that of quasi-static dislocations under static loads, as their self-force is history-dependent, and their evolution of density is rate-relevant. However, the fundamental questions regarding the self-force and evolution of high-speed dislocations in impacted materials is largely unknown. To address this gap, this… More >

Mao Li¹, Xiaobao Tian¹, Wentao Jiang¹, Qingyuan Wang¹, Haidong Fan^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09981

Abstract Poor ductility heavily limits the industrial application of magnesium (Mg) alloys, and pyramidal dislocations are an important deformation mode for ductility enhancement. In this work, discrete dislocation dynamics (DDD) simulations were performed to study the mechanical behavior and dislocation evolution of Mg singlecrystals compressed along c-axis. Especially, basal-transition and cross-slip algorithms of pyramidal dislocations were proposed and introduced in the DDD method. Simulation results show that basaltransition is an important mechanism for the strong strain hardening observed during c-axis compression of Mg single-crystals. Since the basal-transition events are thermally activated, increasing temperature leads to a high strain hardening rate.… More >

Zikun Li¹, Jing Tang¹, Xiaobao Tian¹, Qingyuan Wang¹, Wentao Jiang¹, Haidong Fan^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09968

Abstract Magnesium is a lightweight structural metal but the industrial application is limited by its poor intrinsic ductility. Pyramidal dislocations are believed to be responsible for the ductility enhancement whereas the dislocation plasticity of magnesium was not well studied, especially the pyramidal dislocations. In this work, molecular dynamics simulations were performed to investigate the pyramidal disloation behaviors including the decomposition of pyramidal dislocations on both pyramidal-I and pyramidal-II planes and the interactions between themselves and other dislocations in Mg. The pyramidal-I dislocations are decomposed into and dislocations under shear stress at 0-400K, which all reside on basal plane.… More >

N. Ohno¹, D. Okumura¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 207-214, 2007, DOI:10.3970/icces.2007.004.207

Abstract The self energy of geometrically necessary dislocations (GNDs) is considered to inevitably introduce the higher-order stress work-conjugate to slip gradient in single crystals. It is pointed out that this higher-order stress stepwise changes in response to in-plane slip gradient and thus directly influences the onset of initial yielding in polycrystals. The self energy of GNDs is then incorporated into the strain gradient theory of Gurtin (2002). The resulting theory is applied to model crystal grains of size D, leading to a D-1-dependent term with a coefficient determined by grain shape and orientation. It is thus shown that the self energy… More >

Youngmin Lee, Jae Shin Park, Seyoung Im

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 51-52, 2009, DOI:10.3970/icces.2009.010.051

Abstract We study energetics and mobility of dislocations in silicon crystal in atomistic scale. The electronic structure of silicon affects its dynamics, so that it is analyzed with tight-binding method for high accuracy, emerged as a useful method for studying structural and dynamical properties of covalent systems. The tight biding potential used for silicon crystalline is the one of GSP known as a transferable potential. Due to the nature of rare events, the analysis is executed by action-derived molecular dynamics (ADMD) calculations. The changes of the system energy due to dislocation glide are explored with a view to finding the Peierls… More >

K.P. Baxevanakis¹, A.E. Giannakopoulos²

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.6, pp. 535-544, 2014, DOI:10.3970/cmes.2014.097.535

Abstract This article has no abstract. More >

Jin Ma, Yang Liu, Hongbing Lu, Ranga Komanduri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.1, pp. 41-56, 2006, DOI:10.3970/cmes.2006.016.041

Abstract A multiscale simulation technique coupling three scales, namely, the molecular dynamics (MD) at the atomistic scale, the discrete dislocations at the meso scale and the generalized interpolation material point (GIMP) method at the continuum scale is presented. Discrete dislocations are first coupled with GIMP using the principle of superposition (van der Giessen and Needleman (1995)). A detection band seeded in the MD region is used to pass the dislocations to and from the MD simulations (Shilkrot, Miller and Curtin (2004)). A common domain decomposition scheme for each of the three scales was implemented for parallel processing. Simulations of indentation were… More >

B. Yang², V. K. Tewary³

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.3, pp. 165-178, 2006, DOI:10.3970/cmes.2006.015.165

Abstract Green's function (GF) modeling of defects may take effect only if the GF as well as its various integrals over a line, a surface and/or a volume can be efficiently evaluated. The GF is needed in modeling a point defect, while integrals are needed in modeling line, surface and volumetric defects. In a matrix of multilayered, generally anisotropic and linearly elastic and piezoelectric materials, the GF has been derived by applying 2D Fourier transforms and the Stroh formalism. Its use involves another two dimensions of integration in the Fourier inverse transform. A semi-analytical scheme has been developed previously for efficient… More >

K.P. Baxevanakis¹, A.E. Giannakopoulos²

CMES-Computer Modeling in Engineering & Sciences, Vol.60, No.2, pp. 181-198, 2010, DOI:10.3970/cmes.2010.060.181

Abstract The present work gives a systematic and rigorous implementation of (edge type) circular Volterra dislocation loops in ordinary axisymmetric finite elements using the thermal analogue and the integral representation of dislocations through stresses. The accuracy of the proposed method is studied in problems where analytical solutions exist. The full fields are given for loop dislocations in isotropic and anisotropic crystals and the Peach-Koehler forces are calculated for loops approaching free surfaces and bimaterial interfaces. The results are expected to be very important in the analysis of plastic yield strength, giving quantitative results regarding the influence of grain boundaries, interstitial particles,… More >